Github user NicoK commented on a diff in the pull request:
https://github.com/apache/flink/pull/4552#discussion_r160694722
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/netty/PartitionRequestQueue.java
---
@@ -88,6 +94,37 @@ public void run() {
});
}
+ /**
+ * Try to enqueue the reader once receiving credit notification from
the consumer or receiving
+ * non-empty reader notification from the producer. Only one thread
would trigger the actual
+ * enqueue after checking the reader's availability, so there is no
race condition here.
+ */
+ @VisibleForTesting
+ void triggerEnqueueAvailableReader(final SequenceNumberingViewReader
reader) throws Exception {
+ if (!reader.isRegisteredAvailable() && reader.isAvailable()) {
+ enqueueAvailableReader(reader);
+ }
+ }
+
+ @VisibleForTesting
+ void enqueueAvailableReader(final SequenceNumberingViewReader reader)
throws Exception {
--- End diff --
actually, we can inline this into the first one, make this `private`, and
reduce `Mockito` use in the tests if we just made the `availableReaders` field
accessible to the tests, e.g.
```
/**
* Accesses internal state to verify reader registration in the unit
tests.
*
* <p><strong>Do not use anywhere else!</strong>
*
* @return readers which are enqueued available for transferring data
*/
@VisibleForTesting
ArrayDeque<SequenceNumberingViewReader> getAvailableReaders() {
return availableReaders;
}
```
---
